Let's divide 217709 by 17
The aim is to understand the frequency of 17 in 217709.

Advancing to step 1:
The number 17 fits into 2 0 times, leaving a remainder of 2.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Grab the next digit (1) from the dividend, add it to 2, then carry on: 21 / 17

Moving on to step 2:
17 can be fit into 21 1 times, resulting in a remainder of 4.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Deduct 17 from 21 and we're left with 4.
Grab the next digit (7) from the dividend, add it to 4, then carry on: 47 / 17

Let's proceed to step 3:
47 divided by 17 is 2 with a remainder of 13.
Use 2 as the next digit of our solution. 
Result so far: 12.0
Subtract 34 from 47 to get 13.
Take the next digit (7) from the dividend and append it to 13, then repeat: 137 / 17

Step 4:
The number 17 fits into 137 8 times, leaving a remainder of 1.
The number 8 becomes the next digit in our result. 
Result so far: 128.0
If we subtract 136 from 137, we get 1.
Fetch the next digit (0) from the dividend, attach it to 1 and continue: 10 / 17

Advancing to step 5:
If we divide 10 by 17, we get 0 and a remainder of 10.
The next digit of our result is 0. 
Result so far: 1280.0
If we take 0 away from 10, we end up with 10.
Fetch the next digit (9) from the dividend, attach it to 10 and continue: 109 / 17

Advancing to step 6:
17 can be fit into 109 6 times, resulting in a remainder of 7.
Use 6 as the next digit of our solution. 
Result so far: 12806.0
If we take 102 away from 109, we end up with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Moving on to step 7:
When dividing 70 by 17, we get 4 with a remainder of 2.
Record the quotient 4 as the next digit in the result. 
Result so far: 12806.4
Subtracting 68 from 70 leaves us with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Step 8:
17 goes into 20 1 times with a remainder of 3.
Use 1 as the next digit of our solution. 
Result so far: 12806.41
If we subtract 17 from 20, we get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Advancing to step 9:
17 can be fit into 30 1 times, resulting in a remainder of 13.
Write down 1 as next digit of the result. 
Result so far: 12806.411
If we take 17 away from 30, we end up with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

The final outcome is 12806.411, with a leftover of 0.0013.